Photonic devices are widely used in optical transmission and optical networks. Certain photonic devices operate by being locked to an injected optical signal in order to select one wavelength and/or to ensure stability such as for example providing a constant output frequency. In such conditions, the photonic device may exhibit one or two sets of polarization modes in its transmission or reflection spectra, corresponding to transverse electric (TE) mode and/or transverse magnetic (TM) mode. Therefore, the injection-locking of these devices depends on the state of the polarization of the incoming optical signal, even when the devices exhibit two polarization modes in their spectra.
One example of such devices are the injection-locked laser diodes which are being increasingly used in fiber to the home (FTTH) access networks as an ONU (Optical Network Unit). These laser diodes typically operate on transverse electrical (TE) mode.